Pyrone derivatives from the marine-derived fungus Nigrospora sp. PSU-F18

Pyrones, named nigrosporapyrones A-D (1-4), and five known compounds were isolated from the marine-derived fungus Nigrospora PSU-F18. Their structures were elucidated on the basis of spectroscopic evidence. The antibacterial activity against the standard Staphylococcus aureus ATCC 25923 and methicillin-resistant S. aureus was evaluated.     

Hypocreaterpenes A and B,cadinane-type sesquiterpenes from a marine-derived fungus,Hypocreales sp.

Two new cadinane-type sesquiterpenes, hypocreaterpenes A (1) and B (2), along with five known compounds (3–7) were isolated from a marine-derived fungus Hypocreales sp. strain HLS-104 isolated from a sponge Gelliodes carnosa. Their structures were determined by a combination of spectroscopic methods. All compounds were tested for the inhibitory effects on the nitric oxide (NO) production in lipopolysaccharide (LPS)-treated RAW264.7 cells. Among them, compounds 3 and 6 showed moderate anti-inflammatory activity with average maximum inhibition (E_max) values of 10.22% and 26.46% at 1 μM, respectively.     

Metabolites from the endophytic fungus Phomopsis sp. PSU-D15

From the endophytic fungus Phomopsis sp. PSU-D15, three metabolites named as phomoenamide (1), phomonitroester (2) and deacetylphomoxanthone B (3), were isolated together with three known compounds, dicerandrol A (4), (1S,2S,4S)-p-menthane-1,2,4-triol (5) and uridine. Their structures were elucidated by spectroscopic methods. Phomoenamide (1) exhibited moderate in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Ra.     

Acrocalysterols A and B,two new steroids from endophytic fungus Acrocalymma sp

Two new steroids, named acrocalysterols A (1) and B (2), together with five known compounds were isolated and characterized from an endophytic fungus Acrocalymma sp., isolated from the tender stems of Sinomenium acutum. The structures of the isolated metabolites were identified based on UV, IR NMR (1D and 2D), HR-ESI-TOF-MS, single-crystal X-ray diffraction experiment using Cu Kα radiation and CD spectra associated with TD-DFT calculation. The bioassay showed that compound 2 displayed potent cytotoxicity against three cancer cell lines HeLa, HCC-1806, and RKO with IC₅₀ values ranging from 18.37 to 19.64 μM.     

Structural characterization and antioxidant properties of an exopolysaccharide produced by the mangrove endophytic fungus Aspergillus sp. Y16

A homogeneous exopolysaccharide, designated As1-1, was obtained from the culture medium of the mangrove endophytic fungus Aspergillus sp. Y16 and purified by anion-exchange and gel-permeation chromatography. Results of chemical and spectroscopic analyses, including one- and two-dimensional nuclear magnetic resonance (1D and 2D NMR) spectroscopy showed that As1-1 was mainly composed of mannose with small amounts of galactose, and that its molecular weight was about 15 kDa. The backbone of As1-1 mainly consists of (1 → 2)-linked α-d-mannopyranose units, substituted at C-6 by the (1 → 6)-linked α-d-mannopyranose, (1→)-linked β-d-galactofuranose and (1→)-linked β-d-mannopyranose units. As1-1 possessed good in vitro antioxidant activity as evaluated by scavenging assays involving 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide radicals. The investigation demonstrated that As1-1 is an exopolysaccharide different from those of other marine microorganisms, and could be a potential antioxidant and food supplement.     

An antibacterial cytochalasin derivative from the marine-derived fungus Diaporthaceae sp. PSU-SP2/4

A new pentacyclic cytochalasin (diaporthalasin, 1) and a new ethyl trihydroxytridecatrienoate (diaporthacol, 2) together with five known compounds, R-mevalonolactone (4), dothiorelone C (5), (4S,7S,13S)-4,7-dihydroxy-1,3-tetradeca-1,5-dienolide (6), 4β-acetoxy-9β,10β,15α-trihydroxyprobotrydial (7) and O-methyldihydrobotrydial (8) were isolated from the marine-derived fungus Diaporthaceae sp. PSU-SP2/4. The structures were established by spectroscopic techniques. Compound 1 displayed significant antibacterial activity against both Staphylococcus aureus and methicillin-resistant S. aureus with equal MIC values of 2 μg/mL.     

Toxic polyketides produced by Fusarium sp., an endophytic fungus isolated from Melia azedarach

A new isocoumarin derivative named fusariumin (1), together with two known related resorcylic acid lactones aigialomycin D (2) and pochonin N (3), has been isolated from the cultures of Fusarium sp. LN-10, an endophytic fungus originated from the leaves of Melia azedarach. Their structures were established on the basis of extensive spectroscopic analyzes including 1D- and 2D- NMR (¹H-¹H COSY, HSQC, HMBC, and NOESY) experiments. Compounds 1-3 displayed significant growth inhibitory activity against the brine shrimp (Artemia salina).     

Polyketides from Penicillium sp. JP-1, an endophytic fungus associated with the mangrove plant Aegiceras corniculatum

Four polyketides, leptosphaerone C (1), penicillenone (2), arugosin I (3) and 9-demethyl FR-901235 (4), as well as five known compounds, bacillosporin A (5), bacillosporin C (6), sequoiamonascin D (7), sequoiatone A (8), and sequoiatone B (9) were isolated from the Penicillium sp. JP-1, an endophytic fungus isolated from Aegiceras corniculatum. Their structures were determined by spectroscopic methods, mainly by 2D NMR spectroscopic analyses. Compound 1 showed cytotoxicity against A-549 cells with an IC50 value of 1.45 microM, while compound 2 showed cytotoxicity against P388 cells with an IC50 value of 1.38 microM.     

Secondary metabolite chemistry of the marine-derived fungus Massarina sp., strain CNT-016

Chemical investigation of the culture broth extracts of the marine-derived fungus Massarina sp. (strain CNT-016) has yielded two secondary metabolites, spiromassaritone (1) and massariphenone (2), as well as the previously reported fungal metabolites 6-epi-5'-hydroxy-mycosporulone (3) and enalin A (4). The structures of these compounds were established by a variety of one- and two-dimensional NMR experiments, while the relative configuration of spiromassaritone (1) was determined by X-ray crystallographic methods. The fungal strain was isolated as a sterile mycelium from an ocean mud sample and identified using ITS sequence analysis.     

Austdiol,fulvic acid and citromycetin derivatives from an endolichenic fungus,Myxotrichum sp.

A new austdiol analog myxodiol A (1), three novel fulvic acid derivatives myxotrichin A–C (2–4), and a new citromycetin analog myxotrichin D (5), were isolated from an endolichenic fungus Myxotrichum sp. inhabiting the lichen Cetraria islandica (L.) Ach. The structures of these compounds were elucidated unequivocally on the basis of comprehensive analysis of MS and NMR data. Compounds 2 and 5 displayed very weak cytotoxicity against human leukemia cell line K562, and compounds 1 showed very weak antifungal activity against Candida albicans (sc5314).     

Phomoxins B and C: polyketides from an endophytic fungus of the genus Eupenicillium

Chemical investigations of the culture broth from an endophytic fungus Eupenicillium sp. have afforded two natural products phomoxins B (1) and C (2) as well as the previously reported fungal metabolite eupenoxide (3). Compounds 1 and 2 both contain a cyclic carbonate moiety that is rare among natural products. This paper reports the full spectroscopic characterisation of phomoxins B (1) and C (2) by NMR, UV, IR and MS data. All compounds were inactive against a panel of nosocomial microbes.     

Anthracobic acids A and B, two polyketides, produced by an endophytic fungus Anthracobia sp

Two new polyketides, anthracobic acids A and B (1 and 2, resp.), were isolated from a cultured endophytic fungus, Anthracobia sp. The NMR study revealed that both anthracobic acids contain a carboxylic acid conjugated tetraene attached to an octahydronaphthalene moiety. Both compounds showed antimicrobial activity.     

Chemistry and weak antimicrobial activities of phomopsins produced by mangrove endophytic fungus Phomopsis sp. ZSU-H76

Three metabolites named phomopsin A (1), B (2) and C (3), together with two known compounds cytosporone B (4) and C (5), were isolated from the mangrove endophytic fungus, Phomopsis sp. ZSU-H76 obtained from the South China Sea. Their structures were elucidated by spectroscopic methods, mainly by 1D and 2D NMR spectroscopic techniques. The medium-sized cyclic phenol ether based on 1 or 2 is rare in natural products. In bioassays, compounds 1, 2, and 3 had no significant antibiotic activities, but compounds 4 and 5 inhibited two fungi Candida albicans and Fusarium oxysporum with an MIC ranging from 32 to 64 microg/ml.     

Itaconic acid derivatives and diketopiperazine from the marine-derived fungus Aspergillus aculeatus CRI322-03

Three metabolites, pre-aurantiamine (1), (−)-9-hydroxyhexylitaconic acid (4) and (−)-9-hydroxyhexylitaconic acid-4-methyl ester (5), together with two known compounds, paraherquamide E (6) and secalonic acid D (7), were isolated from the marine-derived fungus, Aspergillus aculeatus.     

NF kappa B inhibitors and antitrypanosomal metabolites from endophytic fungus Penicillium sp. isolated from Limonium tubiflorum

Chemical investigation of the endophytic fungus Penicillium sp. isolated from Limonium tubiflorum growing in Egypt afforded four new compounds of polyketide origin, including two macrolides, penilactone (1) and 10,11-epoxycurvularin (2), a dianthrone, neobulgarone G (7), and a sulfinylcoumarin, sulfimarin (14), along with twelve known metabolites (3-6, 8-13, 15 and 16). The structures of all compounds were assigned by comprehensive spectral analysis (1D and 2D NMR) and mass spectrometry. Compounds 3, 4, 13 and 16 showed pronounced antitrypanosomal activity with mean MIC values ranging from 4.96 to 9.75 ??M. Moreover, when tested against a panel of three human tumor cell lines compounds 3, 4, 6 and 12 showed selective growth inhibition against Jurkat and U937 cell lines with IC₅₀ values ranging from 1.8 to 13.3 ??M. The latter compounds also inhibited TNF??-induced NF-??B activity in K562 cells with IC₅₀ values ranging from 1.6 to 10.1 ??M, respectively.     

Metabolites from the endophytic fungus Xylaria sp. PSU-D14

Glucoside derivatives, xylarosides A (1) and B (2), were isolated from the broth extract of the endophytic fungus Xylaria sp. PSU-D14 along with two known compounds, sordaricin (3) and 2,3-dihydro-5-hydroxy-2-methyl-4H-1-benzopyran-4-one (4). The structures were assigned by spectroscopic methods. Sordaricin (3), one of the known metabolites, exhibited moderate antifungal activity against Candida albicans ATCC90028 with a MIC value of 32 microg/ml.     

A new lateral root growth inhibitor from the sponge-derived fungus Aspergillus sp. LS45

Two new γ-lactones, aspergilactones A (1) and B (2), were discovered along with two known compounds, annularin A (3) and pericoterpenoid A (4), from a culture of the sponge-associated fungus Aspergillus sp. LS45. The planar structures of 1–4 were characterized using comprehensive spectroscopic methods and comparison with literature data. The absolute configurations of 1 and 2 were determined by comparison of electronic circular dichroism (ECD) spectroscopic and optical rotation data with those of known analogues as well as calculated ECD analysis. Compounds 1–4 were tested in a variety of bioassays, and both 1 and 4 exhibited significant inhibition against the lateral root growth of Arabidopsis thaliana Columbia-0 at a concentration of 100 μM. In addition, the in vitro cytotoxic activities of 1–4 against six human cancer cell lines CCRF-CEM, K562, BGC823, AGS, HCT-116 and MDA-MB-231 were evaluated. Compound 4 showed moderate inhibitory effects on CCRF-CEM and K562 cancer cell lines with IC₅₀ values of 13.8 ± 1.6 and 12.9 ± 2.5 μM, respectively. However, compounds 1–4 did not show any notable AChE inhibitory activity in vitro.     

Coprismycins A and B, neuroprotective phenylpyridines from the dung beetle-associated bacterium, Streptomyces sp

Two new phenylpyridines, named coprismycins A and B (1 and 2), and previously reported dipyridines (3-6) were isolated from a culture of Streptomyces sp. associated with the dung beetle, Copris tripartitus. The structures of the coprismycins (1 and 2) were elucidated by the analysis of 1D and 2D NMR spectra and mass, UV, and IR spectra. Coprismycins A-B (1 and 2) and dipyridines (5 and 6) displayed comparable neuroprotective effects against MPP(+) (1-methyl-4-phenylpyrimidium)-induced neurotoxicity in neuroblastoma SH-SY5Y cells.     

A cyclic carbonate and related polyketides from a marine-derived fungus of the genus Phoma

Two metabolites, phomoxin and phomoxide, as well as the previously synthesized antibiotic eupenoxide, have been isolated from the fermentation broth of a marine-derived fungus of the genus Phoma (strain CNC-651). The new compounds are highly oxygenated polyketides of a new structural class. Phomoxin contains an unusual cyclic carbonate functionality that is rare among natural products. The structures of the new metabolites were assigned by spectroscopic methods that relied heavily on 2D NMR spectroscopic analysis.     

Structure and antioxidant activity of an extracellular polysaccharide from coral-associated fungus, Aspergillus versicolor LCJ-5-4

An extracellular polysaccharide AVP was isolated from the fermented broth of coral-associated fungus Aspergillus versicolor LCJ-5-4. AVP was a mannoglucan with molecular weight of about 7 kDa, and the molar ratio of glucose and mannose was 1.7:1.0. On the basis of detailed one- and two-dimensional nuclear magnetic resonance (1D and 2D NMR) spectroscopic analyses, the backbone of AVP was characterized to be composed of (1 → 6)-linked α-d-glucopyranose and (1 → 2)-linked α-d-mannopyranose units. The mannopyranose residues in the backbone were substituted mainly at C-6 by the side chain of (1 → 2)-linked α-d-mannopyranose trisaccharides units. The antioxidant activity of AVP was evaluated with the scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide and hydroxyl radicals in vitro, and the results indicated that AVP had good antioxidant activity, especially scavenging ability on superoxide radicals. AVP was a novel extracellular polysaccharide with different structural characteristics from other extracellular polysaccharides and could be a potential source of antioxidant.